Device for automatic control of the fuel supply to diesel engines



ug- 1963 CARL-GUSTAV s. JOHANSSON ,3

DEVICE FOR AUTOMATIC CONTROL OF THE FUEL SUPPLY TO DIESEL ENGINES FiledDec. 8, 1966 S/NVEN TOR B vubww 'i, fim

United States Patent ice 3,398,731 DEVICE FOR AUTOMATIC CONTROL OF THEFUEL SUPPLY TO DIESEL ENGINES Carl-Gustav Simon Johansson, Molndal,Sweden, assignor, by mesne assignments, to Aktiebolaget Gylling & Co.,Stockholm, Sweden Filed Dec. 8, 1966, Ser. No. 600,206 Claims priority,application Sweden, June 22, 1966, 8,511/66 8 Claims. (Cl. 123-198)ABSTRACT OF THE DISCLOSURE A device for automatic cutting off the fuelsupply conduit to diesel engines of the kind provided with a charginggenerator, an electric battery, a start relay and a key lock. Anadditional relay is coupled between the generator and earth having acore connected to a switch in a current circuit to the positive pole ofthe battery via an off position of the key lock to a solenoid. Theoperation of the generator serves to energize the additional relay toclose the switch and the solenoid is adapted at current passage in thecircuit to cut off the fuel supply conduit.

In order to stop a diesel engine one must in one way or another throttlethe feed of fuel to the motor. This is commonly achieved by means ofsome kind of a mechanical throttle device, e.g., by means of a pull orpush control means on the instrument panel. For the sake of safety it isof importance that this control means is left in throttling positionwhen a car provided with a diesel motor is parked. Should namely the carbe parked in a slope with a gear in and the manual brake not betightened sutficiently, the weight of the car proper may cause the motorto rotate whereby it is started and the car will thereupon be driven bymeans of the motor. Many mechanical devices are known for obtaining thethrottling of the fuel feed but it is common for all of them that theyare easily brought out of function.

The present invention has reference to a device where the fuel supply isthrottled by means of a key lock similar to the ignition lock of a cardriven by means of gasoline and remains throttled until the motor isstarted next time. The main feature of the invention is to be seentherein that a relay is connected between the generator of the car andearth this relay adapted when passed through by current to close acontact in a current circuit from the positive pole of the car batteryvia the zero position of the key lock to a solenoid which is adaptedwhen passed through by current to cut ofi the fuel supply. The deviceconsiderably facilitates the manipulation of diesel engines and theengine is simultaneously kept cut off until it is started next time.

According to a preferred embodiment of the invention there is inserted athrottle valve in the fuel conduit to the engine and this valve isadapted to be closed by means of an axial displacement of an armature ofsaid solenoid at the passage of current through the same. The armatureis preferably kept in attracted position by means of a latch behind anabutment on the armature, said latch adapted to be brought, when anothersolenoid, a releaser solenoid is passed through by current, to releasedposition away from said abutment in such a way that the throttle valveis automatically opened.

In the following the invention will be elucidated with reference to theaccompanying drawing. In the drawing:

FIG. 1 shows a coupling diagram of a device according to the invention,and

FIG. 2 shows partly diagrammatically a longitudinal section through aregulation device comprised in the coupling.

3,398,731 Patented Aug. 27, 1968 The device comprises a key lock 1 thecoupling arm 2 of which can take three positions, viz. a zero positionA, an intermediate position B and a start position C. The coupling arm 2is in a common way returned from last mentioned position to the couplingposition B by means of a spring. The coupling arm 2 is provided with asliding contact 3 which in the dilferent positions coacts with thecoupling plates 4, 5, and 6, respectively, of the key lock. The devicefurther comprises a coupling relay 7 the solenoid 8 of which isconnected to the charge generator 10 of the diesel engine 9 and earth.The contact 11 of the coupling relay 7 is connected in a conduit 12 fromthe control device 14 (FIG. 2). This control device also comprises asecond solenoid 15 which is connected in a conduit 16 between thecontact sheet 6 and earth. From the conduit 16 also issues a conduit 17to the start relay 18 of the engine 9 for connecting its start motor 19.In the conduit 20 from the generator 10 to the solenoid 8 of thecoupling relay 7 there is connected a diode 21 and in the conduit 22from the contact sheet 5 of the key lock 1 to the solenoid 8 there isalso connected a diode 23. To the conduit 22 there are also connectedother electrical means 24 of the car, e.g., direction indicators, theradio, a

cigarette lighter, etc.

In FIG. 2 there is shown a valve housing 26 in the fuel supply conduit25 to the engine 9, this valve housing 26 provided with a seat 27 avalve body 28 tightening against this seat 27. The valve spindle 29 isprovided with a flange 30 and between this flange 30 and an end piece 31on the valve housing 26 there is inserted a helical spring 32. On theouter end of the valve spindle 29 there is arranged a nipple 33, thelatter provided with a loop 34, and one end of a steel wire 35 isattached to said loop 34. The opposite end of the wire is attached toanother helical spring 36 having a greater stiffness than the spring 32.The opposite end of the spring 36 is attached to a loop bolt 37 in oneend of an armature 38 which is displaceable in the solenoid 13. On anelongation portion 39 of the armature 38 there is arranged an abutment40 in the shape of a flange and a latch 41 may be swung in behind thisabutment, said latch arranged on one end of a two-armed lever 42 thearms of which have different lengths. Said arms are journalled on atransverse shaft 43. By means of a helical spring 44 which can be set bymeans of a set screw 45 the latch is kept in contact against theelongation piece 39 or in latching position behind the abutment 40.There a'buts against the long arm 46 of the lever 42 a downwardlydirected elongation portion 47 on an armature 48 which is verticallydisplaccable through the solenoid 15.

When the diesel engine 9 is out of operation the coupling arm 2 of thelock 1 will take the position A for the reason that none of theelectrical means of the car is connected. When the diesel engine is tobe started, the coupling arm 2 is turned past the position B to theposition C. As in common ignition locks last mentioned position shall bespring loaded such that one has to hold the hand on the key (not shown)belonging to the lock 1 during the start period. A current flows fromthe positive pole of the electric battery 49 to the releaser solenoid 15of the control device 14 whereby the armature 48 is pushed downwards andswings the lever 42 in clockwise direction so that the latch 41 islifted from the abutment 40 and frees the armature 38. The spring 32then opens the valve 28. Simultaneously also the start relay 18 isconnected to the battery 49 which brings the start motor to rotatewhereby the diesel engine 9 is started. When the engine has started, onehas to release the key such that the coupling 2 automatically returns tothe position B whereby the start engine is disconnected.

In the position B a current flows from the positive pole 3 of thebattery 49 via the diode 23 to the solenoid 8 of the start relay 7. Thediode 21 prevents this current from reaching further in the directiontowards the generator if the latter should not already have reached fullvoltage. Simultaneously the other electric means 24 of the car areconnected.

When the diesel engine 9 is to be stopped, the coupling arm 2 of the keylock 1 is turned to the position A. The relay 7 will still be attractedfor the reason that the genertaor 10 is charging and a current flows viathe diode 21 through the solenoid 8 to earth. The diode 23 prevents thiscurrent from reaching the other electric means 24 of the car. When thecoupling arm 2 is in the position A, a current circuit is closed via thecontact 11 in such a way that the main solenoid 13 of the control device14 will receive current and attracts the armature 38 which in turncauses the valve 28 to close and the engine to stop. The generator 10will then cease to charge and the relay 7 therefor falls and the currentto the main solenoid 13 is cut off. When the armature 38 was attractedby the main solenoid 13, the lever 42 was swung in counter clockwisedirection by the spring 44 whereby the latch engaged behind the abutment40. Hereby the armature 38 will remain in attracted position, whichmeans that the valve 28 in the fuel supply conduit 25 is closed.

When the diesel engine 9 is to be restarted, the coupling arm 2 of thekey lock 1 is brought to take the position C whereby the releasersolenoid is fed with current. This causes the armature 48 to beattracted in such a way that the latch 41 is released and frees thearmature 38 whereupon the course of event described is repeated.

The sliding contact 3 on the coupling arm 2 of the key lock 1 and alsothe contact sheets 4 and 5 are shaped in such a way that the connectionwith the contact sheet 5 is not cut oif until the contact has beenclosed also over the contact sheet 4 in such a way that the current fromthe positive pole of the battery 49 can be obtained temporarily on onehand via the sliding contact 3 of the coupling arm 2 and on the otherhand via the contact sheet 4 to the main solenoid 13 for the reason thatthe relay 7 then keeps the contact 11 closed. The purpose of this deviceis, if for any reason the diesel engine 9 does not start and there isnot obtained any supply to the solenoid of the coupling relay 7, toensure that a current nevertheless will reach to pass the contact 11 forattracting the main solenoid 13 of the control device 14 before therelay 7 falls.

The invention has been described in the aforegoing for purposes ofillustration only and is not intended to be limited by this descriptionor otherwise except as defined in the appended claims. Thus, the meanscomprised in the coupling may be modified in many Ways without departurefrom the inventive idea. This is true in first hand for the shaping ofthe throttle valve 28 and the control device 14 for the operation ofthis valve.

What I claim is:

1. In a device for automatic cutting ofi the fuel supply 4. conduit todiesel engines of the kind provided with charging generator, an electricbattery, a start relay and a key lock, an additional relay coupledbetween said generator and earth, said additional relay having a coreconnected to a switch in a current circuit to the positive pole of saidbattery via an off position of the key lock to a solenoid, operation ofsaid generator serving to energize said additional relay to close saidswitch, said solenoid adapted at current passage in said circuit to cutofi the fuel supply conduit.

2. A device as claimed in claim 1, in which a throttle valve isconnected in said fuel supply conduit, said valve adapted to be closedby an axial displacement of an armature of said solenoid at currentpassage through the latter.

3. A device as claimed in claim 2, in which a releaser solenoid isconnected between a start position of the key lock and earth, saidreleaser solenoid adapted at current passage to influence a latch forretaining said armature in a position closing the throttle valve.

4. A device as claimed in claim 1 in which a throttl valve is connectedin said fuel supply conduit, said valve adapted to be closed by an axialdisplacement of an armature of said solenoid at current passage throughthe latter, a releaser solenoid connected between a start position ofthe key lock and earth, said releaser solenoid adapted at currentpassage to influence a latch for retaining said armature in a positionclosing the throttle valve.

5. A device as claimed in claim 3, in which said armature is providedwith an abutment or equivalent means adapted to be engaged by said latchand said latch at current passage through the releaser solenoid, to bebrought to releasing position away from said abutment.

6. A device as claimed in claim 1, in which a semiconductor is connectedbetween said generator and said additional relay.

' 7. A device as claimed in claim 1, in which a diode is connectedbetween said generator and said relay.

8. A device as claimed in claim 1, in which said key lock is providedwith a coupling arm, said coupling arm adapted to render possible atemporary and simultaneous connection between the battery and on onehand said additional relay and on the other hand said solenoid.

References Cited UNITED STATES PATENTS 2,423,728 7/1947 Ray 123-1982,771,068 11/1956 Jettinghotf 123198 2,469,942 5/1949 Armstrong et a1.123198 2,924,209 2/1960 Schott 123-179 FOREIGN PATENTS 364,227 1/ 1932Great Britain. 610,439 12/ 1960 Canada.

WENDELL E. BURNS, Primary Examiner.

